Objective: To refit a old movable screen fluoroscopy unit in to a new fluoroscopy unit based on image intensifier in order to improve image quality and reduce radiation dose. Methods:A SIEMENS image intensifier (type X1611,Φ210mm), WAT-120N+CCD and display units replaced a old fluorescent screen unit. According to WS76-2011and GBZ130-2013 national standards, performance comparisons between the old and new fluoroscopy unit were made to use quality control test devices and radiation dosemeters, including low and high contrast revolutions, brightness, entrance surface air kerma rate and ambient dose equivalent rate. Results:The new fluoroscopy unit has become more quality than the old fluoroscopy unit, such as low contrast revolution improved from 7 mm (4%)to 3 mm (4%), high contrast revolution from 0.8 lp/mm to 1.2 lp/mm, brightness increased 255 times. In addition, the entrance surface air kerma rate of patient and the ambient dose equivalent rate for operating position decreased 54.2%and 82%respectively. Conclusion:It was a good approach to use image intensifier instead of fluorescent screen for some small rural hospitals because some small hospitals lack the special fund to purchase modern X-ray radiography units.%目的:通过改造旧式移动式荧光屏透视机,使其成为以影像增强器为基础的透视机,改善影像质量和降低辐射剂量。方法:使用SIEMENS X1611型(Φ210 mm)影像增强器、WAT-120N+CCD和显示器替换荧光屏器件,并分别对改装前后的设备使用剂量仪器、防护仪、亮度仪、低分辨以及高分辨卡等模体进行性能和防护检测;检测标准按照国家标准WS76-2011和GBZ130-2013要求进行。结果:改装后的设备较改装前性能和防护质量有极大的改善,其低对比分辨力达到4%,3 mm,高对比分辨力由0.8l p/mm提高到1.2l p/mm,亮度提高255倍;受检者入射体表空气比释动能率降低54.2%,工作人员操作位的周围剂量当量率降低82%。结论:使用增强器代替荧光屏更适用于小型农村医院,可解决医院由于缺乏专项资金而无法购置新式X射线摄影机的问题。
展开▼